The present disclosure relates to an aircraft wing rib, in particular, although not exclusively, to an aircraft wing rib having an integrated suction conduit which can form part of a hybrid laminar flow control (HLFC) system. The disclosure also relates to an aircraft wing and an aircraft.
There is continued focus in the aviation industry on reducing the fuel consumption and emissions of aircraft. It is possible to reduce fuel consumption and emissions by reducing the airframe drag, which can be achieved by ensuring laminar flow over the windswept surfaces of the wings. The wing shape can be designed to help maintain a laminar boundary layer. However, as the cruise Mach number increases, for example beyond Mach 0.70, it becomes increasingly difficult for the wing shape alone to maintain a laminar boundary layer. This is due at least in part to the increased Reynolds number and sweep.
Hybrid laminar flow control (HLFC) systems have been considered for aircraft in an attempt to stabilise the laminar boundary layer, thereby delaying boundary layer transition. These systems typically work by applying a negative pressure to the windswept surfaces. The term “negative pressure” in this context refers to a pressure less than the pressure at the windswept surface (i.e. negative with respect to a zero-referenced pressure at the windswept surface). It is known to apply a HLFC system to a fin in order to stabilise the laminar boundary layer. However, incorporating an HLFC system into a wing presents more challenges as space within the wing is typically limited as other systems such as high-lift/shielding devices and/or ice protection systems also must also be accommodated in this region.
Embodiments aim to address at least some of the above problems to some extent.